The conventional procedure by medical practitioners for drawing blood from, or injecting a substance into, a live host body, has been for years to do the following steps:
1. Sterilizing the skin to be punctured by vigorous abrasive rubbing with an alcohol swab, PA0 2. removing a needle or cannula from a needle case and inserting it into a syringe holder fitted with a vacutainer or a drug-containing syringe, PA0 3. injecting through the skin in the swabbed area and drawing blood or injecting a drug, PA0 4. destroying the needle, PA0 5. removing and labeling of the vacutainer containing the sample (if blood has been taken), PA0 6. swabbing the wound to disinfect and remove blood leaking from the wound, and PA0 7. covering the wound with a covering.
This practice continues, even though it is now well recognized that alcohol swabbing of the skin is inadequate protection from infection. Not only is the alcohol swab deficient in skin cleansing, but also the cannula can be contaminated and require cleansing. Alcohol is bactericidal against vegetative forms of bacteria through the denaturation of cellular proteins; however, it is far from ideal as a skin or surface disinfectant. Alcohol is flammable, it evaporates too fast to be very effective (it should remain on the skin surface for about 10 minutes), and it dries and irritates the skin.
It would thus be highly desirable to provide a means for sterilizing human skin prior to venipuncture, without abrasion, and in the same step provide protection from infection of the patient by the needle and continued protection of the patient after injection while minimizing the potential of infection of others by the patient's blood as a result of aerosols, leakage from the wound, handling of a swab before dressing the wound, or leakage from the cannula.
Some early attempts have been made to provide alternate procedures. For example, U.S. Pat. No. 3,367,332 (1968) teaches the use of a resealable patch and membrane bandage through which the needle is inserted (FIG. 3), at least the bandage having been sterilized with an antiseptic prior to injection of the host. However, the patch does not contain a sterilizing agent, so that the needle encounters only a thin layer of the sterilizing agent presented by the membrane. Furthermore, although the membrane may be thin and transparent, the patch is not and has substantial thickness, so that the phlebotomist is unable to correctly identify the injection site by sight or by feel, through the patch. In the case of a blood draw, stabbing "in the dark" is unacceptable. For these and other reasons, the technology of this patent has failed to replace the traditional use of alcohol swabs, deficient though the latter might be.
Thus, prior to this invention there has been a need for a sterilizing medium to be used with a needle, and a method of phlebotomy or drug injection, that more adequately sterilizes the needle while permitting precise location of the injection site.